The U.S. government has raised the possibility that extreme ultraviolet (EUV) lithography equipment made by Dutch chip equipment company ASML may have been brought into China. ASML fully denied any EUV tools being in China and dismissed the suspicions.

TechCrunch reported on June 19 that ASML said in a statement: "EUV equipment has never been in China," rebutting suspicions raised by the U.S. government.

The controversy erupted after it became known that U.S. Commerce Secretary Howard Lutnick conveyed related concerns in a meeting with ASML executives. The U.S. government claims it has secured indications that EUV-related parts and transport equipment from ASML were brought into China. It did not disclose evidence that a complete EUV system is actually in China. The U.S. Commerce Department also did not give a specific answer when asked whether EUV equipment is in China.

The controversy is drawing attention because of the strategic importance of EUV equipment. EUV is viewed as essential for producing advanced semiconductors at 3 nanometres and below. ASML is currently the only company in the world able to produce EUV lithography tools. Advanced semiconductors made by TSMC, as well as the latest AI and mobile chips from Nvidia and Apple, also depend on ASML’s EUV equipment.

If EUV equipment was actually brought into China, assessments say it could create a major crack in the U.S. semiconductor export-control system toward China that has been built over years. The United States has effectively blocked exports of ASML’s EUV equipment to China in cooperation with the Dutch government since the first Trump administration.

ASML Chief Executive Christophe Fouquet (크리스토프 푸케) strongly rebutted the claim. He said ASML tracks every EUV tool it has shipped, and that the machines are either operating at customer facilities or have been retrieved and returned to the company. He also said access rights to core EUV technologies, documents and training materials are strictly controlled, and that local staff in China are run separately so they cannot access that information.

ASML also says it would be difficult for China to obtain or replicate EUV quickly on technical grounds. Fouquet said: "ASML’s EUV technology was completed on top of technological capabilities accumulated over decades," adding: "Developing the core technology, the EUV light source alone, took 20 years." He added that since China has never obtained actual equipment, reverse engineering would also not be easy.

Analysts also say there is little business incentive to take the risk of smuggling EUV equipment. ASML is currently selling older deep ultraviolet (DUV) lithography tools to China. The company says this is business permitted within a range that maintains the technology gap.

ASML forecasts about 20 percent of its total revenue in 2026 will come from sales to China. It argues the likelihood of illicit transfers is low because violating EUV export controls could endanger not only its China revenue but also its position in global markets.

The suspicions, however, have not been fully resolved. With the U.S. government not disclosing evidence, the U.S. claims and ASML’s explanation currently diverge.

The United States is also speeding up efforts to secure next-generation lithography technology. The U.S. Commerce Department announced late last year a plan to provide up to $150 million in support for xLight, a startup developing next-generation light source technology. The industry views the technology as something that could challenge ASML’s EUV technology in the long term. In addition, the U.S. Congress is pushing a bipartisan bill to restrict exports to China not only of EUV but also DUV equipment. The bill passed a key committee in April.

The market is watching whether the U.S. government will disclose additional evidence and whether semiconductor curbs targeting China will be further tightened.